Flooring material

ABSTRACT

A surface element designed to be assembled together with similar surface elements to form a unit of a plurality of joined surface elements; said surface elements comprising a core, a decorative upper surface and edges for joining, including a first and a second edges allowing joining by rotational movement, and a third and a fourth edge allowing joining by vertical movement, wherein two adjacent edges of the surface element at the same time, and concurrently with said rotational movement, is joined with a surface element adjacent to the first edge and a surface element adjacent to the third or fourth edge.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims priority to co-pendingU.S. patent application Ser. No. 14/076,879, filed Nov. 11, 2013, whichis a continuation of Ser. No. 12/010,587 (now U.S. Pat. No. 8,578,675),filed Jan. 28, 2008, which is a divisional of U.S. patent applicationSer. No. 10/242,674 (now U.S. Pat. No. 7,332,053), which is acontinuation-in-part of U.S. patent application Ser. No. 09/988,014 (nowabandoned), filed Nov. 16, 2001, and a continuation-in-part applicationof U.S. patent application Ser. No. 09/672,076 (now U.S. Pat. No.6,591,568), filed Sep. 29, 2000, which claims priority to SwedishApplication No. 0001149-4, filed Mar. 31, 2000. The entire disclosuresof each of the above references are incorporated by reference herein intheir entireties.

BACKGROUND

The present invention relates to a flooring material comprisingsheet-shaped floor elements which are joined by means of joiningmembers.

Prefabricated floor boards provided with tongue and groove at the edgesare quite common nowadays. These can be installed by the average handyman as they are very easy to install. Such floors can, for example, beconstituted of solid wood, fibre board or particle board. These are mostoften provided with a surface layer such as lacquer, or some kind oflaminate. The boards are most often installed by being glued via tongueand groove. The most common types of tongue and groove are howeverburdened with the disadvantage to form gaps of varying width between thefloor boards in cases where the installer hasn't been thorough enough.Dirt will easily collect in such gaps. Moisture will furthermore enterthe gaps which will cause the core to expand in cases where it is madeof wood, fibre board or particle board, which usually is the case. Theexpansion will cause the surface layer to rise closest to the edges ofthe joint which radically reduces the useful life of the floor since thesurface layer will be exposed to an exceptional wear. Different types oftensioning devices, forcing the floor boards together duringinstallation can be used to avoid such gaps. This operation is howevermore or less awkward. It is therefore desirable to achieve a joint whichis self-guiding and thereby automatically finds the correct position.Such a joint would also be possible to utilise in floors where no glueis to be used.

Such a joint is known through WO 94/26999 which deals with a system tojoin two floor boards. The floor boards are provided with a lockingdevice at the rear sides. In one embodiment the floor boards areprovided with profiles on the lower side at a first long side and shortside. These profiles, which extends outside the floor board itself, isprovided with an upwards directed lip which fits into grooves on thelower side of a corresponding floor board. These grooves are arranged onthe second short side and long side of this floor board. The floorboards are furthermore provided with a traditional tongue and groove onthe edges. The intentions are that the profiles shall bend downwards andthen to snap back into the groove when assembled. The profiles areintegrated with the floor boards through folding or alternatively,through gluing.

According to WO 94/26999, the floor boards may be joined by turning orprizing it into position with the long side edge as a pivot point. It isthen necessary to slide the floor board longitudinally so that it snapsinto the floor board previously installed in the same row. A play isessential in order to achieve that. This play seems to be marked withthe Greek letter Delta in the figures. A tolerance of +−0.2 mm ismentioned in the application. Such a play will naturally cause undesiredgaps between the floor boards. Dirt and moisture can penetrate intothese gaps.

It is also known through WO 97/47834 to manufacture a joint where thefloor boards are joined by turning or prizing it into position with thelong side edge as a pivot point. According to this invention atraditional tongue has been provided with heel on the lower side. Theheel has a counterpart in a recess in the groove of the opposite side ofthe floor board. The lower cheek of the groove will be bent away duringthe assembly and will then snap back when the floor board is in thecorrect position. The snap-joining parts, i.e. the tongue and groove, isin opposite to the invention according to WO 94/26999 above, where theyare constituted by separate parts, seems to be manufacturedmonolithically from the core of the floor board. WO 97/47834 does alsoshow how the tongue and groove with heels and recesses according to theinvention is tooled by means of cutting machining. This invention doesalso have the disadvantage that the best mode of joining floor boardsincludes longitudinal sliding for joining the short sides of the floorboards, which also here will require a play which will cause unwantedgaps between the floor boards. Dirt and moisture can penetrate intothese gaps.

It is, through the present invention, made possible to solve the abovementioned problems whereby a floor element which can be assembledwithout having to be slid along already assembled floor elements hasbeen achieved. It is thereby made possible to achieve tighter joints.Accordingly, the invention relates to a flooring material comprisingsheet-shaped floor elements with a mainly square or rectangular shape.The floor elements are provided with edges, a lower side and an upperdecorative layer. The floor elements are intended to be joined by meansof joining members. The invention is characterised in that:

-   -   a) The floor elements are provided with male joining members on        a first edge while a second, opposite, edge of the floor        elements are provided with a female joining member. The male        joining member is provided with a tongue and a lower side        groove. The female joining member is provided with a groove and        a cheek, the cheek being provided with a lip. The floor elements        are intended to mainly be joined together by tilting the floor        element to be joined with an already installed floor element or        a row of already installed floor elements, with the male joining        member of the floor element angled downwards and that the first        edge is allowed to be mainly parallel to the second edge of the        already installed floor element or elements. The tongue of the        tilted floor element is then inserted into the groove of the        female joining member of the already installed floor element or        elements. The tilted floor element is then turned downwards,        with its lower edge as a pivot axis, so that the lip eventually        snaps into the lower side groove where the decorative upper        layer of the floor elements are mainly parallel.    -   b) The floor elements are moreover provided with a male vertical        assembly joining member on a third edge while a fourth edge is        provided with female vertical assembly joining member. The        fourth edge is arranged on a side opposite to the third edge.    -   c) The floor elements are alternatively provided with a male        vertical assembly joining member on a third edge, while a fourth        edge also is provided with male vertical assembly joining        member. The fourth edge is arranged on a side opposite to the        third edge. Adjacent male vertical assembly joining members are        thereby joined by means of a separate vertical assembly joining        profile. Two adjacent edges of a floor element can hereby be        joined with a floor element adjacent to the first edge and a        floor element adjacent to the third or fourth edge at the same        time, and in the same turning motion.

The force needed to overcome the static friction along the joint betweentwo completely assembled male and female joining members is preferablylarger than 10N per meter of joint length, suitably larger than 100N permeter of joint length.

According to one embodiment of the invention, the floor elements areprovided with male vertical assembly joining members on a third edge andprovided with female vertical assembly joining members on a fourth edge.The male vertical assembly joining members are provided with mainlyvertical lower cheek surfaces arranged parallel to the closest edge. Thelower cheek surfaces are intended to interact with mainly vertical uppercheek surfaces arranged on the female vertical assembly joining membersso that two joined adjacent floor elements are locked against each otherin a horizontal direction. The male and female vertical assembly joiningmembers are provided with one or more snapping hooks with matching undercuts which by being provided with mainly horizontal locking surfaceslimits the vertical movement between two joined adjacent floor elements.

The floor elements may alternatively be provided with male verticalassembly joining members on both a third and a fourth edge. These edgesare then snap joined by means of a vertical assembly profile which onboth sides of a longitudinal symmetry line is designed as a femalevertical assembly joining member according to the description above. Twojoined adjacent floor elements are locked to each other in a horizontaldirection via the vertical assembly profile while, at the same time,vertical movement between two joined adjacent floor elements is limited.

The joint between a third and a fourth edge of two joined floor elementspreferably comprises contact surfaces which are constituted by thehorizontal locking surfaces of the under cuts and hooks, the mainlyvertical upper cheek surfaces and lower cheek surfaces as well as uppermating surfaces.

The joint between two joined floor elements suitably also comprisescavities.

According to one embodiment of the invention the snapping hook isconstituted by a separate spring part which is placed in a cavity.Alternatively the undercut is constituted by a separate spring partwhich is placed in a cavity. The spring part is suitably constituted byan extruded thermoplastic profile, a profile of thermosetting resin oran extruded metal profile.

The vertical assembly joining profiles are suitably shaped as extendedprofiles which suitably are manufactured through extrusion which is awell known and rational method. The vertical assembly joining profilesare suitably shaped as extended lengths or rolls which can be cut to thedesired length. The length of the vertical assembly joining profilesconsiderably exceeds the length of a floor element, before being cut.The lateral joints of the floor will only need shorter pieces ofvertical assembly joining profiles which are positioned as each newfloor board is introduced to a row. Vertical assembly joining profilesaccording to the present invention may be manufactured of a number ofdifferent materials and manufacturing methods. Among the most suitedcan, however, be mentioned injection moulding and extrusion. Suitablematerials are thermoplastic materials such as polyolefins, polystyrene,polyvinyl chloride or acrylnitrile-butadiene-styrene copolymer. Thesemay suitably be filled with, for example, wood powder or lime in orderto increase the rigidity but also to increase the adhesion when glue isused. It is also possible to mill a vertical assembly joining profilefrom a material such as wood, fibre board or particle board.

The flooring material including the floor boards and joining profilesabove is most suited when installing floors where it isn't desired touse glue. It is, however, possible to use glue or twin-faced adhesivetape in order to make the installation irreversibly permanent. The glueor tape is then suitably applied on, or in connection to, possiblecavities or faces below the upper mating surfaces.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described further in connection to enclosed figuresshowing different embodiments of a flooring material whereby,

FIG. 1 shows, in cross-section, a first and a second edge 2 ^(I) and 2^(II) respectively, during joining.

FIG. 2 shows, in cross-section, a second embodiment of a first and asecond edge 2 ^(I) and 2 ^(II) respectively, during joining.

FIG. 3 shows, in cross-section, a third embodiment of a first and asecond edge 2 ^(I) and 2 ^(II) respectively, during joining.

FIG. 4 shows, in cross-section, a fourth embodiment of a first and asecond edge 2 ^(I) and 2 ^(II) respectively, during joining.

FIG. 5 shows, in cross-section, a third and a fourth edge 2 ^(III) and 2^(IV) respectively, during joining.

FIG. 6 shows, in cross-section, a second embodiment of a third and afourth edge 2 ^(III) and 2 ^(IV) respectively, during joining.

FIG. 7 shows, in cross-section, a third embodiment of a third and afourth edge 2 ^(III) and 2 ^(IV) respectively, during joining.

FIG. 8 shows, in cross-section, a fourth embodiment of a third and afourth edge 2 ^(III) and 2 ^(IV) respectively and a vertical assemblyjoining profile 30, during joining.

DETAILED DESCRIPTION

Accordingly FIG. 1 shows, in cross-section, a first and a second edge 2^(I) and 2 ^(II) respectively, during assembly. The figure shows partsof a flooring material comprising sheet-shaped floor elements 1 with amainly square or rectangular shape. The floor elements 1 are providedwith edges 2, a lower side 5 and an upper decorative layer 3. The floorelements 1 are intended to be joined by means of joining members 10. Thefloor elements 1 are provided with male joining members 10 on a firstedge 2 ^(I) while a second edge 2 ^(II) of the floor elements 1 areprovided with a female joining member 10 ^(II). The second edge 2 ^(II)is arranged on a side opposite to the first edge 2 ^(I). The malejoining member 10 ^(I) is provided with a tongue 11 and a lower side 5groove 12. The female joining member 10 ^(II) is provided with a groove13 and a cheek 14, the cheek 14 being provided with a lip 15. The floorelements 1 are intended to mainly be joined together by tilting thefloor element 1 to be joined with an already installed floor element 1or a row of already installed floor elements 1, with the male joiningmember 10 ^(I) of the floor element 1 angled downwards and that thefirst edge 2 ^(I) is allowed to be mainly parallel to the second edge 2^(II) of the already installed floor element 1 or elements 1. The tongue11 of the tilted floor element 1 is then inserted into the groove 13 ofthe female joining member 10 ^(II) of the already installed floorelement 1 or elements 1, whereby the tilted floor element 1 is turneddownwards, with its lower edge as a pivot axis, so that the lip 15eventually falls into the lower side 5 groove 12 where the decorativeupper layer 3 of the floor elements 1 are mainly parallel.

The embodiment shown in FIG. 2 corresponds mainly with the one shown inFIG. 1. The lip 15 and lower side 5 groove 12 are, however, providedwith a cam 16 and a cam groove 17 which provides a snap action locking.

The embodiment shown in FIG. 3 corresponds mainly with the one shown inFIGS. 1 and 2 above. The lip 15 and lower side 5 groove 12 are, however,provided with a cam 16 and a cam groove 17 which provides a snap actionlocking.

The embodiment shown in FIG. 4 corresponds mainly with the one shown inFIG. 1 above. The lip 15 and cheek 14 is however shaped as a thinresilient section which provides a snap action locking.

FIG. 5 shows, in cross-section, a third and a fourth edge 2 ^(III) and 2^(II) respectively, of a floor element 1 according to any of the FIGS. 1to 4. The floor elements 1 are provided with a male vertical assemblyjoining member 10 ^(III) on a third edge 2 ^(III) while a fourth edge 2^(IV) is provided with a female vertical assembly joining member 10^(IV). The fourth edge 2 ^(IV) is placed on a side opposite to the thirdedge 2 ^(III). The male vertical assembly joining members 10 ^(III) areprovided with mainly vertical lower cheek surfaces 21 arranged parallelto the closest edge 2. The lower cheek surfaces 21 are intended tointeract with mainly vertical upper cheek surfaces 22 arranged on thefemale vertical assembly joining members 10 ^(IV) so that two joinedadjacent floor elements 1 are locked against each other in a horizontaldirection. The male vertical assembly joining members 1011 are moreoverprovided with two snapping hooks 23 while the female vertical assemblyjoining members 10 ^(IV) are provided with matching under cuts 24, whichby being provided with mainly horizontal locking surfaces limits thevertical movement between two joined adjacent floor elements 1.

The joint between a third and a fourth edge 2 ^(III) and 2 ^(IV)respectively of two joined floor elements 1 further comprises contactsurfaces which are constituted by the horizontal locking surfaces of theunder cuts 23 and hooks 24, the mainly vertical upper cheek surfaces 22lower cheek surfaces as well as upper mating surfaces 25. The jointbetween two joined floor elements 1 also comprises cavities 6.

Shown at 40, in both FIGS. 6 and 7, are mainly horizontal lockingsurfaces of undercut 24. Specifically, mainly horizontal lockingsurfaces 40 are designed to interact with snapping hook 23 to lock therespective floor elements 1 in place.

The joint between a third and a fourth edge 2 ^(III) and 2 ^(IV)respectively of two joined floor elements 1 further comprises contactsurfaces which are constituted by the horizontal locking surfaces of theunder cuts 24 and hooks 23, the mainly vertical upper cheek surfaces 22lower cheek surfaces as well as upper mating surfaces 25. The jointbetween two joined floor elements 1 also comprise cavities 6.

The embodiment shown in FIG. 7 corresponds in the main with the oneshown in FIG. 6. The snapping hook 23 on the male vertical assemblyjoining member 10 ^(III) is, however, moved somewhat inwards in thefloor element 1 whereby a guiding angle is formed above the undercut 24of the female vertical joining member 10 ^(IV).

The embodiment shown in FIG. 8 corresponds mainly with the one shown inFIG. 7. Both the third and the fourth edges 2 ^(III) and 2 ^(IV)respectively are, however, provided with male vertical assembly joiningmembers 10 ^(III). A vertical assembly joining profile 30, provided witha female vertical assembly joining profile 10 ^(IV) on both sides of avertical symmetry line, is used for joining the two floor elements 1.The female vertical assembly joining members 10 ^(IV) of the verticalassembly joining profile 30 are equipped similar to the female verticalassembly joining members 10 ^(IV) in FIG. 7 above.

Two adjacent edges 2 of a floor element 1 can at the same time, and inthe same turning motion, be joined with a floor element 1 adjacent tothe first edge 2 ^(I) and a floor element 1 adjacent to the third orfourth edge 2 ^(III) and 2 ^(IV) respectively, when assembling floorelements 1 according to the above described embodiments.

The floor elements 1 according to the present invention most oftencomprises a core. The core is most often comprised of particles or fibreof wood bonded with resin or glue. It is advantageous to coat thesurface closest to the joint in cases where the floor will be exposed tohigh levels of moisture since the cellulose based material is sensitiveto moisture. This coating may suitably incorporate resin, wax or somekind of lacquer. It is not necessary to coat the joint when it is to beglued since the glue itself will protect from moisture penetration. Theupper decorative layer 3 is constituted of a decorative paperimpregnated with melamine-formaldehyde resin. One or more so calledoverlay sheets of α-cellulose, impregnated with melamine-formaldehyderesin may possibly be placed on top of the decorative layer. Theabrasion resistance may be improved by sprinkling one or more of thesheets with hard particles of for example α-aluminum oxide, siliconcarbide or silicon oxide. The lower side 5 may suitably be coated withlacquer or a layer of paper and resin.

The invention is not limited by the embodiments shown since they can bevaried within the scope if the invention.

According to a first particularly preferred embodiment, the inventionrelates to flooring material comprising sheet-shaped floor elements witha mainly square or rectangular shape, which floor elements are providedwith edges, a lower side and an upper decorative layer, whereby thefloor elements are joined by means of joining members, the edges beingseparated into a first and a second edge, which first and second edgesare arranged on opposite sides, and a third and a fourth edge beingadjacent to the first and the second edge and which third and fourthedges are arranged on sides opposite to one another, whereby the floorelements are provided with male joining members on the first edge,having a tongue and a lower side groove, and female joining members onthe second edge, having a groove and a cheek, the cheek being providedwith a lip, whereby the floor elements are joined together via the maleand female joining members by tilting the floor element to be joinedwith an already installed floor element or a row of already installedfloor elements, with the male joining member of the floor element angleddownwards, that the first edge is positioned mainly parallel to thesecond edge of the already installed floor element or row of floorelements, whereupon the tongue of the titled floor element is insertedinto the groove of the female joining member of the already installedfloor element or row of floor elements, whereby the tilted floor elementis turned downwards, with its lower edge as a pivot axis, so that thelip eventually snaps into the lower side groove where the decorativeupper layer of the floor elements are mainly parallel, and that thethird and fourth edges of the floor elements are joined by means ofjoining members selected from the group consisting of: a) wherein thefloor elements, on the third edge, are provided with a male verticalassembly joining member while the fourth edge is provided with a femalevertical assembly joining member, the fourth edge being arranged on aside opposite to the third edge, the male vertical assembly joiningmembers being provided with mainly vertical lower cheek surfacesarranged parallel to the third edge, which lower cheek surfaces arearranged to interact with undercuts arranged on the female verticalassembly joining members so that two joined adjacent floor elementsbecomes locked to each other in a horizontal direction, that togetherthe male and female vertical assembly joining members are provided withat least one snapping hook to interact with said undercuts which bybeing provided with a mainly horizontal locking surface limits thevertical movement between two joined adjacent floor elements, wherebythe third edge and the fourth edge are joined with respective edges ofadjacent floor elements through vertical motion, and b) wherein thefloor elements on the third edge, are provided with a male verticalassembly joining member while the fourth edge also is provided with amale vertical assembly joining member, the fourth edge being arranged ona side opposite to the third edge, which adjacent male vertical assemblyjoining members are joined by means of a separate vertical assemblyjoining profile which vertical assembly profile is provided with femalevertical assembly joining member, the male vertical assembly joiningmembers being provided with mainly vertical lower cheek surfacesarranged parallel to either the third or the fourth the edge, whichlower cheek surfaces are arranged to interact with mainly vertical uppercheek surfaces arranged on the female vertical assembly joining membersso that two joined adjacent floor elements becomes locked to each otherin a horizontal direction, that together the male and female verticalassembly joining members are provided with at least one snapping hook tointeract with said undercut which by being provided with a mainlyhorizontal locking surface limits the vertical movement between twojoined adjacent floor elements, whereby the third edge and the fourthedge are joined with respective edges of adjacent floor elements throughvertical motion, whereby two adjacent edges of a floor element at thesame time, and concurrently with the turning motion, is joined with afloor element adjacent to the first edge and a floor element adjacent tothe third or fourth edge.

In such particularly preferred embodiment, the force needed to overcomethe static friction along the joint between two completely assembledmale and female joining members is preferably larger than 10N per meterof joint length.

In such particularly preferred embodiment, the floor elements arepreferably provided with male vertical assembly joining members on athird edge and provided with female vertical assembly joining members ona fourth edge, the male vertical assembly joining members being providedwith mainly vertical lower cheek surfaces arranged parallel to the thirdedge, which lower cheek surfaces are arranged to interact with mainlyvertical upper cheek surfaces arranged on the female vertical assemblyjoining members so that two joined adjacent floor elements becomeslocked to each other in a horizontal direction, that together the maleand female vertical assembly joining members are provided with at leastone snapping hook with matching undercut which by being provided with amainly horizontal locking surface limits the vertical movement betweentwo joined adjacent floor elements.

Preferably, the joint between third and the fourth edge of two joinedfloor elements comprises contact surfaces which are constituted by themainly horizontal locking surfaces of the undercuts and hooks, themainly vertical upper cheek surfaces and lower cheek surfaces as well asupper mating surfaces.

Preferably, the joint between two joined floor elements also comprisescavities.

The said snapping hook can be constituted by a separate spring partplaced in a cavity.

Preferably such spring part is constituted by an extruded thermoplasticprofile.

Preferably, such spring part is constituted by a profile of athermosetting resin.

Alternatively, such spring part is constituted by an extruded metalprofile.

In such particularly preferred embodiment, the undercut may beconstituted by a separate spring part which is placed in a cavity.

Preferably, such spring part is constituted by an extruded thermoplasticprofile.

Alternatively, such spring part is constituted by a profile of athermosetting resin.

Further alternatively, such spring part may be constituted by anextruded metal profile.

In such particularly preferred embodiment, the floor elements may becoated with twin-faced adhesive tape or glue.

In such particularly preferred embodiment, the joining members may becoated with twin-faced adhesive tape or glue.

In such particularly preferred embodiment, the force needed to overcomethe static friction along the joint between two completely assembledmale and female joining members is preferably larger than 100N per meterof joint length.

According to a second particularly preferred embodiment, the inventionrelates to a surface element designed to be assembled together withsimilar surface elements to form a unit of a plurality of joined surfaceelements; said surface elements comprising a core, a decorative uppersurface and edges for joining, at least one of said edges for joiningcomprising a cavity, and a separate spring part placed in said cavity.

In such particularly preferred embodiment, the spring part is preferablyformed of thermoplastic.

Alternatively, such spring part is formed of thermosetting resin or ofmetal.

Such spring part may comprise a snapping hook or an undercut.

In such second particularly preferred embodiment, the decorative surfacepreferably comprises a laminate or a lacquer.

The invention further relates to an assembled unit of a plurality ofsurface elements described herein above. Clearly, such assembled unit ofsurface elements preferably is characterized in that the edges forjoining comprise a male joining element and female joining element on anopposite side edge, and third and fourth joining edges, the male andfemale joining elements capable of being joined by tilting the surfaceelements and relatively inserting the tongue into the groove andrelatively turning downwards the surface elements towards one anotherand at least one of the third and fourth edges comprising the springpart.

What is claimed is:
 1. A surface element designed to be assembledtogether with similar surface elements to form a plurality of joinedsurface elements: the surface element comprising a decorative uppersurface, an opposed lower surface and at least four edges disposedbetween the upper and lower surfaces, said lower surface defining aplane; the four edges comprising a first edge and a second edge defininga first pair of opposite sides, and a third edge and a fourth edgedefining a second pair of opposite sides; the four edges including upperedge portions, towards which the surface elements seen from abovevisually extend in joined condition; wherein the first edge of thesurface element comprises a first male joining member and the secondedge comprises a first female joining member; the first male joiningmember comprising a distally extending tongue and the first femalejoining member comprising a groove which is bordered by an upper lip anda lower lip, said lower lip forming a lower cheek extending in distaldirection further than said upper lip; the first male joining member andthe first female joining member being configured such that two of suchsurface elements can be coupled and vertically as well as horizontallylocked at their respective first and second edges; the vertical lockingbeing realized in that the tongue fits in the groove, said tongue andgroove providing a positive vertical locking, said tongue theretoextending with a distal length underneath the upper lip, said lengthbeing such that joining of the tongue and groove by only aplane-parallel substantial vertical lowering of one surface element inrespect to the other is made impossible; the horizontal locking beingrealized by an upwardly directed lip at said lower cheek and a lowerside groove at the edge comprising the tongue, said upwardly directedlip and said lower side groove having contact surfaces for realizingsaid horizontal locking; said lower side groove at a distal side thereofbeing bordered by a lower side protrusion at said tongue, saidprotrusion having a lowermost portion; said lowermost portion beinglocated proximally from a vertical plane through the upper edge portionbelonging to said first edge; wherein the third edge of the surfaceelement comprises a second male joining member and the fourth edgecomprises a second female joining member; wherein the third and fourthedges of two of such surface elements when coupled define a verticalclosing plane; said second male joining member and second female joiningmember of the surface element being configured such that two of suchsurface elements at their respective third edge and fourth edge seen ina vertical cross-section perpendicular to said closing plane can becoupled to each other by a non-rotational downward motion of one surfaceelement in respect to the other surface element, wherein saidnon-rotational downward motion seen in said cross-section issubstantially parallel to said vertical closing plane; said second malejoining member being formed as an upper cheek protruding at said thirdedge and provided with a downward directed portion; said second femalejoining member being formed as a lower cheek protruding at said fourthedge and provided with an upward directed portion; said second malejoining member comprising a male cheek surface at a lower side of saidupper cheek and said second female joining member comprising a femalecheek surface at an upper side of said lower cheek, the male and femalecheek surfaces being arranged to interact with one another so that twojoined adjacent floor elements become locked to each other in ahorizontal direction; said third and fourth edges each comprising one ormore locking surfaces for locking the third edge and a fourth edge oftwo of such coupled surface elements against vertical separation;wherein said one or more locking surfaces for locking the third edge andfourth edge against vertical separation define one or more snappinghooks and undercuts configured to engage by a snapping action throughsaid non-rotational downward motion, and when engaged preventingvertical separation of the third edge and fourth edge; wherein saidlower cheek of the second edge is formed in one piece of a core materialof the surface element; wherein the contact surfaces at the first maleand first female joining members in the coupled condition define atleast one first tangent line making an angle with said plane; whereinthe male and female cheek surfaces at the second male and second femalejoining members in the coupled condition of two of such surface elementsdefine at least one second tangent line making an angle with said plane;and wherein said angle defined by said one first tangent line isdifferent from said angle defined by said one second tangent line. 2.The surface element of claim 1, wherein the angle of the second tangentline is larger than the angle of the first tangent line, such that thesecond tangent line with respect to said plane is steeper than saidfirst tangent line.
 3. The surface element of claim 2, wherein saidangle of the first tangent line as well as said angle of the secondtangent line are different from 90 degrees.
 4. The surface element ofclaim 3, wherein the contact surface of the first female joining memberis upwardly directed from a proximal to a distal position.
 5. Thesurface element of claim 4, wherein the female cheek surface of thesecond female joining member is upwardly directed from a proximal to adistal position.
 6. The surface element of claim 1, wherein the joiningmembers at the first, second, third and fourth edges are configured suchthat the joining motion that is required for joining the surface elementwith its first edge to a second edge of a similar adjacent secondsurface element, automatically results in the joining of the surfaceelement with its third edge to a fourth edge of an adjacent thirdsurface element.
 7. The surface element of claim 1, wherein also thelower cheek of the fourth edge is formed in one piece of said corematerial.
 8. The surface element of claim 1, wherein said contactsurfaces for realizing said horizontal locking at the first pair ofopposite sides are substantially planar.
 9. The surface element of claim1, wherein said contact surfaces for realizing said horizontal lockingat the first pair of opposite sides are curved.
 10. The surface elementof claim 1, wherein the second male joining member and the second femalejoining member are formed in one piece from said core material.